Abstract

Tea is one of the important plantation crops in Nepal. One of the important fungal pathogens Sclerotium rolfsii causing seedling blight disease in tea was found to be predominant in the nursery grown plants. Alternations in antigenic patterns following induction of resistance of in susceptible tea plant were detected using immunological assays. These antigenic changes, owing to calixin treatment, that was analyzed using immune-diffusion tests, have some significance in the resistance of tea to Sclerotium rolfsii. PTA-ELISA formats and PAb of Sclerotium rolfsii, treated and untreated plants exposed to natural inoculum of S. rolfsii after 15 and 30 days of soil amendments, detection of S. rolfsii in tea root tissues and rhizosphere soil of different treatment with pathogen , bio-control agents and systemic fungicides determined immunologically in both root tissues , soil and antigens prepared from mycelia of S. rolfsii, amendment soils tested on nitrocellulose paper PAbs raised against mycelia of S. rolfsii using NBT/BCIP as substrate. Following PTA-ELISA with PAb raised against mycelia of S. rolfsii, it could be inferred that the absorbance (A405) values were always lesser in treated root tissues in comparison to healthy untreated ones. PTA-ELISA of tea root tissues and rhizosphere soil of different treatment with pathogen and bio-control agents reacted with PAbs of S. rolfsii. Trichoderma harzianum and T. viride showed the reduction of pathogen population in rhizosphere soil and root. Reaction of various amended soil antigens with of S. rolfsii. The amended soil antigens inoculated with S. rolfsii showed lesser colour intensity on nitrocellulose membranes than homologous antigen of S. rolfsii. In conclusion, by application of bio-control agents, plant extracts, systemic fungicides and organic amendments in tea roots and soil reduce intensity of sclerotial blight disease.